#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll MOD = 1000000007;
ll mpow(ll x, ll y){
if(!y) return 1;
if(y%2) return mpow(x, y-1) * x % MOD;
ll tmp = mpow(x, y/2);
return tmp * tmp % MOD;
}
ll modInv(ll x){
return mpow(x, MOD-2);
}
int n, k;
ll a[502], b[502];
ll arr[1002];
void input();
void init();
void solve();
void output();
int main(){
input();
init();
solve();
output();
}
void input(){
vector<int> vec;
scanf("%d", &n);
for(int i=1; i<=n; i++){
scanf("%lld %lld", &a[i], &b[i]);
a[i]--;
vec.push_back(a[i]);
vec.push_back(b[i]);
}
vec.push_back(0);
sort(vec.begin(), vec.end());
vec.erase(unique(vec.begin(), vec.end()), vec.end());
k = (int)vec.size() - 1;
for(int i=0; i<=k; i++) arr[i] = vec[i];
for(int i=1; i<=n; i++){
a[i] = lower_bound(arr, arr+k+1, a[i]) - arr + 1;
b[i] = lower_bound(arr, arr+k+1, b[i]) - arr;
}
}
ll nCk[502][502];
ll xCi[1002][502];
ll xySum[1002][502];
void init(){
/// nCk
for(int i=0; i<=n; i++){
nCk[i][0] = nCk[i][i] = 1;
for(int j=1; j<i; j++){
nCk[i][j] = (nCk[i-1][j] + nCk[i-1][j-1]) % MOD;
}
}
/// xCi
for(int i=1; i<=k; i++){
ll X = arr[i] - arr[i-1];
xCi[i][1] = X;
for(int j=2; j<=n; j++){
xCi[i][j] = xCi[i][j-1] * (X-j+1) % MOD * modInv(j) % MOD;
}
}
/// xyMult
for(int i=1; i<=k; i++){
for(int j=1; j<=n; j++){
for(int d=1; d<=j; d++){
xySum[i][j] = (xySum[i][j] + xCi[i][d] * nCk[j-1][d-1]) % MOD;
}
}
}
}
int sum[502][1002];
ll DP[502][1002];
ll DPsum[502][1002];
void solve(){
/// sum
for(int i=1; i<=n; i++){
for(int j=a[i]; j<=b[i]; j++){
sum[i][j] = 1;
}
}
for(int j=1; j<=k; j++) for(int i=1; i<=n; i++) sum[i][j] += sum[i-1][j];
DP[0][0] = 1;
for(int i=0; i<=k; i++) DPsum[0][i] = 1;
for(int i=1; i<=n; i++){
for(int j=1; j<=k; j++){
if(j < a[i] || b[i] < j) continue;
for(int prv=0; prv<i; prv++){
DP[i][j] = (DP[i][j] + DPsum[prv][j-1] * xySum[j][sum[i][j]-sum[prv][j]]) % MOD;
}
}
for(int j=1; j<=k; j++) DPsum[i][j] = (DPsum[i][j-1] + DP[i][j]) % MOD;
// for(int j=1; j<=k; j++) printf("%lld ", DP[i][j]);
// puts("");
}
}
ll ans;
void output(){
for(int i=1; i<=n; i++){
for(int j=1; j<=k; j++){
ans = (ans + DP[i][j]) % MOD;
}
}
printf("%lld", ans);
}
Compilation message
boat.cpp: In function 'void input()':
boat.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
37 | scanf("%d", &n);
| ~~~~~^~~~~~~~~~
boat.cpp:39:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
39 | scanf("%lld %lld", &a[i], &b[i]);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
619 ms |
17908 KB |
Output is correct |
2 |
Correct |
630 ms |
17960 KB |
Output is correct |
3 |
Correct |
623 ms |
17852 KB |
Output is correct |
4 |
Correct |
619 ms |
17832 KB |
Output is correct |
5 |
Correct |
619 ms |
17968 KB |
Output is correct |
6 |
Correct |
622 ms |
18104 KB |
Output is correct |
7 |
Correct |
625 ms |
18052 KB |
Output is correct |
8 |
Correct |
620 ms |
18044 KB |
Output is correct |
9 |
Correct |
618 ms |
17988 KB |
Output is correct |
10 |
Correct |
620 ms |
18000 KB |
Output is correct |
11 |
Correct |
625 ms |
17920 KB |
Output is correct |
12 |
Correct |
623 ms |
17920 KB |
Output is correct |
13 |
Correct |
618 ms |
18048 KB |
Output is correct |
14 |
Correct |
617 ms |
18036 KB |
Output is correct |
15 |
Correct |
622 ms |
18112 KB |
Output is correct |
16 |
Correct |
114 ms |
10344 KB |
Output is correct |
17 |
Correct |
120 ms |
10412 KB |
Output is correct |
18 |
Correct |
124 ms |
10384 KB |
Output is correct |
19 |
Correct |
121 ms |
10420 KB |
Output is correct |
20 |
Correct |
119 ms |
10332 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
619 ms |
17908 KB |
Output is correct |
2 |
Correct |
630 ms |
17960 KB |
Output is correct |
3 |
Correct |
623 ms |
17852 KB |
Output is correct |
4 |
Correct |
619 ms |
17832 KB |
Output is correct |
5 |
Correct |
619 ms |
17968 KB |
Output is correct |
6 |
Correct |
622 ms |
18104 KB |
Output is correct |
7 |
Correct |
625 ms |
18052 KB |
Output is correct |
8 |
Correct |
620 ms |
18044 KB |
Output is correct |
9 |
Correct |
618 ms |
17988 KB |
Output is correct |
10 |
Correct |
620 ms |
18000 KB |
Output is correct |
11 |
Correct |
625 ms |
17920 KB |
Output is correct |
12 |
Correct |
623 ms |
17920 KB |
Output is correct |
13 |
Correct |
618 ms |
18048 KB |
Output is correct |
14 |
Correct |
617 ms |
18036 KB |
Output is correct |
15 |
Correct |
622 ms |
18112 KB |
Output is correct |
16 |
Correct |
114 ms |
10344 KB |
Output is correct |
17 |
Correct |
120 ms |
10412 KB |
Output is correct |
18 |
Correct |
124 ms |
10384 KB |
Output is correct |
19 |
Correct |
121 ms |
10420 KB |
Output is correct |
20 |
Correct |
119 ms |
10332 KB |
Output is correct |
21 |
Correct |
732 ms |
18412 KB |
Output is correct |
22 |
Correct |
737 ms |
18436 KB |
Output is correct |
23 |
Correct |
747 ms |
18248 KB |
Output is correct |
24 |
Correct |
728 ms |
18108 KB |
Output is correct |
25 |
Correct |
720 ms |
18276 KB |
Output is correct |
26 |
Correct |
772 ms |
18772 KB |
Output is correct |
27 |
Correct |
780 ms |
18932 KB |
Output is correct |
28 |
Correct |
768 ms |
18736 KB |
Output is correct |
29 |
Correct |
775 ms |
18648 KB |
Output is correct |
30 |
Correct |
637 ms |
18024 KB |
Output is correct |
31 |
Correct |
622 ms |
18060 KB |
Output is correct |
32 |
Correct |
647 ms |
17956 KB |
Output is correct |
33 |
Correct |
616 ms |
17996 KB |
Output is correct |
34 |
Correct |
634 ms |
18104 KB |
Output is correct |
35 |
Correct |
624 ms |
18072 KB |
Output is correct |
36 |
Correct |
618 ms |
17912 KB |
Output is correct |
37 |
Correct |
622 ms |
18052 KB |
Output is correct |
38 |
Correct |
621 ms |
17872 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
12 ms |
3668 KB |
Output is correct |
2 |
Correct |
12 ms |
3636 KB |
Output is correct |
3 |
Correct |
12 ms |
3668 KB |
Output is correct |
4 |
Correct |
14 ms |
3680 KB |
Output is correct |
5 |
Correct |
13 ms |
3688 KB |
Output is correct |
6 |
Correct |
15 ms |
3668 KB |
Output is correct |
7 |
Correct |
14 ms |
3668 KB |
Output is correct |
8 |
Correct |
16 ms |
3716 KB |
Output is correct |
9 |
Correct |
13 ms |
3668 KB |
Output is correct |
10 |
Correct |
13 ms |
3652 KB |
Output is correct |
11 |
Correct |
12 ms |
3636 KB |
Output is correct |
12 |
Correct |
12 ms |
3632 KB |
Output is correct |
13 |
Correct |
13 ms |
3656 KB |
Output is correct |
14 |
Correct |
12 ms |
3660 KB |
Output is correct |
15 |
Correct |
12 ms |
3668 KB |
Output is correct |
16 |
Correct |
8 ms |
2880 KB |
Output is correct |
17 |
Correct |
7 ms |
2864 KB |
Output is correct |
18 |
Correct |
8 ms |
2900 KB |
Output is correct |
19 |
Correct |
8 ms |
2900 KB |
Output is correct |
20 |
Correct |
8 ms |
2868 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
619 ms |
17908 KB |
Output is correct |
2 |
Correct |
630 ms |
17960 KB |
Output is correct |
3 |
Correct |
623 ms |
17852 KB |
Output is correct |
4 |
Correct |
619 ms |
17832 KB |
Output is correct |
5 |
Correct |
619 ms |
17968 KB |
Output is correct |
6 |
Correct |
622 ms |
18104 KB |
Output is correct |
7 |
Correct |
625 ms |
18052 KB |
Output is correct |
8 |
Correct |
620 ms |
18044 KB |
Output is correct |
9 |
Correct |
618 ms |
17988 KB |
Output is correct |
10 |
Correct |
620 ms |
18000 KB |
Output is correct |
11 |
Correct |
625 ms |
17920 KB |
Output is correct |
12 |
Correct |
623 ms |
17920 KB |
Output is correct |
13 |
Correct |
618 ms |
18048 KB |
Output is correct |
14 |
Correct |
617 ms |
18036 KB |
Output is correct |
15 |
Correct |
622 ms |
18112 KB |
Output is correct |
16 |
Correct |
114 ms |
10344 KB |
Output is correct |
17 |
Correct |
120 ms |
10412 KB |
Output is correct |
18 |
Correct |
124 ms |
10384 KB |
Output is correct |
19 |
Correct |
121 ms |
10420 KB |
Output is correct |
20 |
Correct |
119 ms |
10332 KB |
Output is correct |
21 |
Correct |
732 ms |
18412 KB |
Output is correct |
22 |
Correct |
737 ms |
18436 KB |
Output is correct |
23 |
Correct |
747 ms |
18248 KB |
Output is correct |
24 |
Correct |
728 ms |
18108 KB |
Output is correct |
25 |
Correct |
720 ms |
18276 KB |
Output is correct |
26 |
Correct |
772 ms |
18772 KB |
Output is correct |
27 |
Correct |
780 ms |
18932 KB |
Output is correct |
28 |
Correct |
768 ms |
18736 KB |
Output is correct |
29 |
Correct |
775 ms |
18648 KB |
Output is correct |
30 |
Correct |
637 ms |
18024 KB |
Output is correct |
31 |
Correct |
622 ms |
18060 KB |
Output is correct |
32 |
Correct |
647 ms |
17956 KB |
Output is correct |
33 |
Correct |
616 ms |
17996 KB |
Output is correct |
34 |
Correct |
634 ms |
18104 KB |
Output is correct |
35 |
Correct |
624 ms |
18072 KB |
Output is correct |
36 |
Correct |
618 ms |
17912 KB |
Output is correct |
37 |
Correct |
622 ms |
18052 KB |
Output is correct |
38 |
Correct |
621 ms |
17872 KB |
Output is correct |
39 |
Correct |
12 ms |
3668 KB |
Output is correct |
40 |
Correct |
12 ms |
3636 KB |
Output is correct |
41 |
Correct |
12 ms |
3668 KB |
Output is correct |
42 |
Correct |
14 ms |
3680 KB |
Output is correct |
43 |
Correct |
13 ms |
3688 KB |
Output is correct |
44 |
Correct |
15 ms |
3668 KB |
Output is correct |
45 |
Correct |
14 ms |
3668 KB |
Output is correct |
46 |
Correct |
16 ms |
3716 KB |
Output is correct |
47 |
Correct |
13 ms |
3668 KB |
Output is correct |
48 |
Correct |
13 ms |
3652 KB |
Output is correct |
49 |
Correct |
12 ms |
3636 KB |
Output is correct |
50 |
Correct |
12 ms |
3632 KB |
Output is correct |
51 |
Correct |
13 ms |
3656 KB |
Output is correct |
52 |
Correct |
12 ms |
3660 KB |
Output is correct |
53 |
Correct |
12 ms |
3668 KB |
Output is correct |
54 |
Correct |
8 ms |
2880 KB |
Output is correct |
55 |
Correct |
7 ms |
2864 KB |
Output is correct |
56 |
Correct |
8 ms |
2900 KB |
Output is correct |
57 |
Correct |
8 ms |
2900 KB |
Output is correct |
58 |
Correct |
8 ms |
2868 KB |
Output is correct |
59 |
Correct |
816 ms |
19136 KB |
Output is correct |
60 |
Correct |
802 ms |
19084 KB |
Output is correct |
61 |
Correct |
788 ms |
18892 KB |
Output is correct |
62 |
Correct |
814 ms |
19068 KB |
Output is correct |
63 |
Correct |
794 ms |
19176 KB |
Output is correct |
64 |
Correct |
908 ms |
19948 KB |
Output is correct |
65 |
Correct |
887 ms |
19876 KB |
Output is correct |
66 |
Correct |
885 ms |
19968 KB |
Output is correct |
67 |
Correct |
897 ms |
19920 KB |
Output is correct |
68 |
Correct |
885 ms |
19972 KB |
Output is correct |
69 |
Correct |
767 ms |
19048 KB |
Output is correct |
70 |
Correct |
754 ms |
19216 KB |
Output is correct |
71 |
Correct |
744 ms |
19076 KB |
Output is correct |
72 |
Correct |
754 ms |
19008 KB |
Output is correct |
73 |
Correct |
765 ms |
19144 KB |
Output is correct |
74 |
Correct |
149 ms |
10612 KB |
Output is correct |
75 |
Correct |
155 ms |
10700 KB |
Output is correct |
76 |
Correct |
154 ms |
10700 KB |
Output is correct |
77 |
Correct |
151 ms |
10668 KB |
Output is correct |
78 |
Correct |
148 ms |
10636 KB |
Output is correct |